move rpc_setup to the last step of __init__

rpc setup should be the last stuff in agent initialization
so that the rcp message handler(the agent instance itself)
can have a fully initialized agent instance.

Change-Id: I58c966e2c8ee92c307b565932e867b5d1ec73b67
Closes-Bug: #1259088
Merge "move rpc_setup to the last step of __init__"